The present technology relates to a solid-state imaging device and a manufacturing method, and more particularly, to a solid-state imaging device and a manufacturing method capable of improving a crosstalk characteristic between comparators constituting AD converters in adjacent columns without a side effect, for example, in a solid-state imaging device such as an image sensor including a so-called column parallel type AD conversion unit having a plurality of AD converters arranged in a row direction.
An example of a solid-state imaging device that captures an image includes a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In recent years, a CMOS image sensor is attracting attention due to requests for miniaturization or the like.
The CMOS image sensor includes an AD conversion unit that AD (Analog to Digital) converts an analog electrical signal output by a pixel, which performs photoelectric conversion. As the AD conversion unit of the CMOS image sensor, a column parallel type AD conversion unit (hereinafter also referred to as a column parallel AD conversion unit) capable of performing, in parallel, AD conversion on electrical signals output by two or more pixels such as all of a plurality of pixels arranged in one row output is adopted from a request of high-speed processing or the like (Japanese Patent No. 4470700).
The column parallel AD conversion unit is configured, for example, by arranging a plurality of ADCs (AD Converters) the number of which is equal to the number of columns of pixels, side by side in a row direction, and the ADC in each column performs AD conversion of the electrical signal output by the pixel in the column.
An example of the ADC constituting the column parallel AD conversion unit includes a so-called reference signal comparison-type ADC that includes a comparator and a counter and performs AD conversion of an electrical signal output by the pixel by comparing a predetermined reference signal with the electrical signal.
An example of the reference signal comparison type ADC includes a single-slope ADC.
In the single-slope ADC, an electrical signal output by a pixel is AD-converted by a comparator comparing a reference signal whose level is changed at a constant slope, such as a ramp signal, with the electrical signal output by the pixel, and a counter counting a time necessary for a change of the level of the reference signal until the levels of the reference signal and the electrical signal match (Japanese Patent No. 4470700).